It is well known in the art that different requirements are put on rail vehicle slack adjusters. Generally speaking, these requirements are the same irrespective of whether the slack adjuster is of the so called axial type used as a self-contained cylinder-shaped member with slack-adjusting function in a rail vehicle brake rigging or is combined with a brake cylinder to a brake unit for use at a wheel or disc to be braked.
However, as the slack adjuster with which the present invention is concerned is primarily designed for use in a brake unit, the requirements on brake unit adjusters are of most interest in this case. The invention is, however, also applicable to axial type adjusters, and no limitation to a brake unit adjuster is intended.
The present invention is concerned with a so called one-nut adjuster, i.e. the design and function is entirely based on the use of one nut in engagement with a spindle. There is presently a tendency towards more frequent use of this type of adjuster, as such a design can be made simpler, cheaper, and more compact than a two-nut design. Numerous examples of this general type are known in the art.
Other requirements on an adjuster of this type is that it shall have a high mechanical efficiency and high accuracy as regards the obtained slack under differing working conditions. Further the design shall be sturdy and easy to protect against the influence from the harsh environment. It shall --when need arises--be easily serviceable. Last but not least the design shall be easy to adopt to different sizes and working lengths with a minimum number of differing parts.